1. Field of the Invention
This invention relates to inhibition of warmed-over flavor in meat. More particularly, it relates to methods and compounds for inhibiting warmed-over flavor using selected cations.
2. Description of Related Art
It has been long known that meat (e.g. beef, poultry, pork, fish) which is cooked and then stored at refrigerated temperatures may develop a rancid or stale flavor. Development of such flavors may occur in a relatively short period of time, generally much shorter than the time required for spoiling of raw meat. This phenomenon has come to be known in the industry as "warmed-over flavor" (abbreviated "WOF").
There are many contexts in which cooked meat is refrigerated and then reheated for consumption, for example, leftovers, school luncheons, microwavable dinners, airline foods, fast foods, delicatessen foods, parbaked and even frozen pizzas, and the like. Development of WOF can adversely affect the palatability of meat in all of these situations and thus poses a significant problem.
Various treatments have been proposed to address this problem. For example, the meat may be cured with agents such as nitrites or nitrates. For reasons which heretofore have not been entirely understood, cured meat does not generally develop WOF. However, curing tends to impart a salty, smoked flavor and is thus unacceptable in many contexts. Also, nitrites are thought to be fairly carcinogenic as they may be converted to nitrosamines at the gastric pH, thereby effectuating damage to DNA.
Another treatment which has been proposed is mixing chitin or carboxymethyl chitosan into ground meat. However, this treatment appears to be limited to use with ground meat, presumably due to the large molecular size of these biopolymers, hindering their ability to diffuse very far into meat.
Another treatment involves application of a compound capable of scavenging oxygen radicals. Examples of such compounds are BHA, BHT, TBHQ, propyl gallate, alphatocopherol, and rosemary extract. However, scavengers have been shown to exert only minor effects on WOF development, presumably since oxygen radicals are not completely responsible for the chemical breakdown leading to WOF.
Application of sodium tripolyphosphates ("STPP") has also been suggested, but sometimes imparts a soapy texture on the meat. Furthermore, STPP contains a significant amount of sodium and thus may not be commercially acceptable.
Use of polyvalent cation chelators such as EDTA have been proposed but are not always effective.
Viscous marinades (e.g. gravies) are sometimes used in an attempt to retard oxygen diffusion into the meat, but are generally ineffective for that purpose.
Other approaches, similar to marinades, have been employed as well, including the use of film-forming or coating agents to retard oxygen diffusion into meats. Substances composed of cross-linking agents in combination with food polymers such as alginate, pectin, HPMC (hydroxypropyl methyl cellulose), methylcellulose and even carboxymethyl cellulose have been proposed for use as enrobing agents to prevent oxygen uptake by the coated meat product. For example, when calcium is combined with alginate, a "gelling" reaction occurs between the two agents, leading to the development of a crusty coating or film that can be applied to the exterior of food which may or may not aid in retarding oxygen uptake (see, e.g. Wanstedt et al., 1981; and U.S. Pat. No. 3,395,024).
Enrobing or film-forming agents have not found widespread use in the food industry in WOF preventatives in that they are generally ineffective for this purpose and even found to impart an undesirable texture.
Accordingly, there is a continuing need to develop materials and methods for treating meat to inhibit the development of WOF. It is therefore an object of this invention to provide treatments which address at least some of the disadvantages experienced in the art.